The overall object of the proposed research is to assure a continuing year round supply of fertile sea urchins as a research resource. There will be a close examination of the fertility of sea urchins derived from special deep water sites as a function of season. In general it is known that sea urchins are fertile for several months during the year, and we intend to extend this knowledge to a more precise and detailed level for the chosen locality, the Pt. Loma kelp bed near San Diego, CA. New projects include development of methods for identifying stages of oogenesis; measurement of the ability of various collected populations of gravid sea urchins to produce practical quantities of mature oocytes; studies of inbreeding in isolated micropopulations; mapping of selected areas of the Pt. Loma bed; and experimentation with environmental variables affecting annual cycles of oogenesis.